This application is based on Patent Application No. 2001-308828 filed Oct. 4, 2001 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a card connector provided with an ejecting mechanism capable of selectively ejecting a card mounted thereon.
2. Description of the Related Art
Various functions of electronic equipments such as a cellular phone, telephone, PDA (personal digital assistant) or camera have been extended by mounting thereon, via a card connector of the respective equipment, an IC card in which a central processing unit (CPU) or an IC for memory is incorporated, such as a SIM (subscriber identity module) card, an MMC (MULTI-MEDIA CARD; trade mark) or an SD (secure digital) card; a MEMORY STICK (trade mark); or a SMART MEDIA (trade mark).
The card connector for detachably mounting such an IC card thereto comprises a base member having a plurality of contact terminals to be electrically connected to electrode pads in the IC card for selectively accommodating the IC card, an ejecting mechanism provided at the base member for selectively ejecting the IC card accommodating within the base member outward, and a cover member for covering the base member and the ejecting mechanism, as disclosed in Japanese Patent Application Laid-open Nos. 2000-251025 and 2000-251024.
A chamber for accommodating the IC card is defined by combining the base member with the cover member. The base member is formed, for example, of resinous material and the cover member is formed of metallic material.
The ejecting mechanism comprises, for example, an ejector for selectively guiding the mounted IC card toward an open end or the chamber of the card connector, and a cam mechanism for locking or unlocking the ejector relative to the card chamber.
The cam mechanism mainly comprises as an element, for example, a coil spring for biasing the ejector toward the open end of the card connector, a cam portion in which a guide groove is formed and a cam follower member (a rocking arm) movably engaging at the other end thereof with the guide groove.
One end of the coil spring is engaged with the ejector, while the other end of the coil spring is brought into contact with the inner surface of an end of the base member.
When the IC card is mounted to the chamber, the ejector of the ejecting mechanism is pressed by a front end of the IC card against the biasing force of the coil spring to engage one end of the rocking arm with a predetermined position of the guide groove and hold the same there, whereby the ejecting mechanism is maintained in the locked state to hold the IC card at the predetermined position.
Also, when the IC card is removed from the chamber, the IC card is again pushed in the same direction such that the one end of the rocking arm is disengaged from the predetermined position in the guide groove to release. Thus, the ejecting mechanism becomes in an unlocked state whereby the ejector is made to move toward the open end of the card connector by the biasing force of the coil spring. As a result, part of the IC card is pushed out from the chamber.
In the assembly of the above-mentioned ejecting mechanism, the coil spring is disposed between the above-mentioned ejector and the inner surface of the base member while being compressed by a predetermined amount from a free length thereof.
Thereafter, when a portion of the contact terminal in the completed card connector to be soldered is electrically bonded by reflow soldering (including lead-free solder such as tin-silver or tin-silver-copper; this is also true hereinafter) to an electrode of a substrate in an electronic equipment, there is a risk in that the base member molded with resin may become deformed under the influence of the heat during the soldering and the biasing force of the coil spring. While it would be thought to thicken the thickness of the base member as a countermeasure thereto, this is not advantageous because this is reverse to the requirement for thinning the card connector.
In view of such a problem, an object of the present invention is to provide a card connector having an ejecting mechanism for selectively discharging the mounted card, capable of avoiding the undesirable heat distortion of a base member even though a section of a contact terminal to be soldered is electrically bonded by the reflow soldering.
To achieve the above object, a card connector of the present invention comprises a base member having contact terminals to be electrically connected to electrodes of a card and a card accommodating chamber for selectively mounting the card, and an ejecting mechanism provided at the base member, the ejecting mechanism comprising an ejector disposed in the base member for selectively discharging the card and a biasing member for biasing the ejector; a cover member formed of heat-resistant material for covering the base member and the ejecting mechanism; wherein one end of the biasing member is engaged with the ejector and the other end of the biasing member is held by the cover member.
The biasing member may be held between the stopper member disposed on one side of the cover member for restricting a position of the ejector and the inner surface of the other end of the cover member via the ejector.
The base member may be formed of electrically insulating material and the cover member may be formed of metal sheet.
As apparent from the above description, according to the card connector of the present invention, since one end of the biasing member is engaged with the ejector and the other end of the biasing member is held by the cover member made of heat-resistant material and the cover member covering the ejecting mechanism and the base member, the biasing force is not applied to the base member. Accordingly, even if the portion of the contact terminal to be soldered is electrically connected to the electronic equipment by the reflow soldering, undesirable heat distortion is avoidable in the base member.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings.